While doctors recognize that individuals with gum disease are at greater risk for heart disease, gum disease isn't currently considered a standard risk factor for heart disease.

"We report evidence that introduction of oral bacteria into the bloodstream in mice increased risk factors for atherosclerotic heart disease,” said study investigator Irina M. Velsko, a graduate medical student in the University of Florida. “Our hope is that the American Heart Association will acknowledge causal links between oral disease and increased heart disease. That will change how physicians diagnose and treat heart disease patients.”

The study also implies that brushing teeth clean, flossing and regular visits to the dentist can directly lower the risk of developing heart disease later in life. Caused by bacteria, gum disease impacts 46 percent of the US population, while heart disease is the top cause of death in North America – the study team said. The American Heart Association published a statement in 2012 linking gum and heart disease, but did not find a cause-and-effect relationship.

In the new study, the scientists infected mice with four gum-disease bacteria and followed their progression. As soon as the bacteria were seen in the mouse gums, heart and aorta – the study scientists said they saw an uptick in risk factors, such as cholesterol and inflammation, related to disease.

“The mouth is the gateway to the body and our data provides one more piece of a growing body of research that points to direct connections between oral health and systemic health," said study investigator Kesavalu Lakshmyya, from the University of Florida's Department of Periodontology.

"In Western medicine there is a disconnect between oral health and general health in the rest of the body; Dentistry is a separate field of study from Medicine,” Lakshmyya noted.

The new study is actually part of a bigger research project funded by the National Institutes of Health/National Institute of Dental and Craniofacial Research and focused on how gum disease affects overall health.

"Our intent is to increase physician awareness of links between oral bacterial infection and heart disease," said study investigator Alexandra Lucas, a cardiologist at the University of Florida. “Understanding the importance of treating gum disease in patients with heart disease will lead to future studies and recommendations for careful attention to oral health in order to protect patients against heart disease.”

Another study published last year by Journal of Alzheimer’s Disease found a connection between gum disease and Alzheimer’s disease. In the study, researchers discovered that subjects with Alzheimer’s showed the presence of products from Porphyromonas gingivalis bacteria in the brain. P. gingivalis is the most common cause of chronic gum disease.

“We are working on the theory that when the brain is repeatedly exposed to bacteria and/or their debris from our gums, subsequent immune responses may lead to nerve cell death and possibly memory loss,” said study author Sim K. Singhrao, a medical and dental research fellow at the University of Lancashire. “Thus, continued visits to dental hygiene professionals throughout one’s life may be more important than currently envisaged with inferences for health outside of the mouth only.”